Are Lefties More of a Danger on the Road?

Studies seem to show that left-handed drivers are more likely to reflexively veer left into oncoming traffic than they are to swerve to the right, off the road. dlanier/Getty Images

The road for left-handers, in this overwhelmingly right-handed world we live in, has never been an easy one to travel. Especially, it seems, when it comes to driving on an actual road.

Sure, lefties mostly motor their way through life just as well as the rest of us. Mozart and Beethoven, Michelangelo and da Vinci, Gates and Zuckerberg, Clinton and Obama all have proven that.

But let's face it. A most-trusted sidekick is not called a "left-hand man". People who stumble out of left field on two left feet ... yeah, you want no part of them.

Everyday tasks like writing can be an absolute mess for lefties. Opening a can with a hand can-opener? Using scissors? A nightmare.

All sorts of studies have been done on handedness and mortality, with early research (25 years or older) suggesting that lefties die younger. Those findings have been roundly challenged, even discounted by many scholars since then. But new studies pop up all the time showing that lefties are, at the least, more prone to accidents, both on the road and off it.

So, back to driving: Nothing is ever completely proven, but to be on the safe side, it might be best to use a little more caution, lefties.

Maybe the closest we'll get to a real answer on lefties and driving comes from a study by psychologist Stanley Coren, the author of the 1993 book, "The Left-Hander Syndrome: The Causes and Consequences of Left-Handedness." Coren points to a reflex action that may work against left-handed drivers, at least in places where cars operate on the right-hand side of the road (which, of course, is most of the world).

In his study, Coren threw foam rubber balls at people, most of whom reflectively tried to block the ball with their nondominant hand. That'd be bad news if it happened on the interstate at rush hour.

"To relate this reflex to traffic crashes, imagine that the hands are holding a steering wheel and that there is a sudden incident that triggers the driver's defensive reflex. For the right-hander, with the left hand held high and right hand held low, the steering wheel rotates clockwise and the car swerves to the right, off the road or into slower moving traffic. For left-handers the reverse occurs, and the car veers to the left into oncoming traffic."

Cornell psychologist Daniel Casasanto sees that as a completely plausible explanation because of something called "approach and avoidance" actions, which have been physically traced in a kind of emotional map of the brain. The "approach" emotions (things like happiness) were long thought to be gathered in the right side of the brain. The avoidance (disgust, fear) were in the left.

Right Brain Left Brain Flip

But a few years ago, scientists found that those emotions were completely flipped in the brains of left-handers. The approach emotions — you might call that the "good" side — were on the left. The bad (the avoidance emotions) were on the right.

To the left-handed brain, left is good. Right is bad.

"The way we conceptualize emotions depends on the way we use our hands to interact with the world. That's not a theory that anybody had suggested before a few years ago," Casasanto says. "We know it's true because this, 'Right is good, left is bad' that is found across languages and across cultures is also found in the unconscious, in the right-handers' minds. But the exact opposite is found in left-handers' minds, in spite of everything that language and culture is telling us."

Back to the road: If a lefty driver sees something bad on the road ahead, Casasanto suggests, that triggers an avoidance mechanism in the brain. For the lefty, the right hand rises to avoid, either pushing the wheel initially to the left (counter-clockwise) or allowing, even briefly, more pull from the dominant, left-hand (again, counter-clockwise). That, if true, could spell trouble on the road.

(If it seems strange that you'd avoid something or try to block something with your nondominant hand, Casasanto suggests thinking more in a "sword and shield" kind of way. The sword is in your dominant hand. The shield is in the other one.)

Short of going all Mad Max to test these things out in a real-world setting, all this remains hypothesis. But it's an intriguing one. If a little scary for lefties.

We can, at times, ascribe way too much importance to handedness. Like eye color or the color of skin, which way you throw a ball doesn't, in the end, make you more or less human.

"Differences, different traits like handedness, eye color, other things that make people look different from one another," says historian Kushner, "... we shouldn't overly burden them with having some kind of deeper meaning than they actually do."

Still, there is some meaning there. Finding out why some people go left and others right, why and how different people think what they do, matters. It's why scientists have been looking at it for centuries.

"It matters because the way we interact with our environment is a huge part of how we learn," Casasanto says. "And our hands are a really important point of interface between the person and the world."

Now That's Interesting

One question scientists have long struggled with is why left-handers make up only about 10 percent of the world's population. A 2012 study out of Northwestern University offers this theory: "The more social the animal — where cooperation is highly valued — the more the general population will trend toward one side," mathematician Daniel Abrams, the study's author, told Live Science. "The most important factor for an efficient society is a high degree of cooperation. In humans, this has resulted in a right-handed majority."